Post-copulatory sexual selection refers to sperm competition and female cryptic choice, which can both arise from sexual promiscuity(1). Copulating with more than one male may benefit to females directly (by increasing their fertility or probability to mate with better partners for instance), or indirectly through positive effects on their offspring (by increasing their genetic diversity or viability for instance)(1). In some species with internal fertilization, females are able to store sperm in specific storage organs. Cryptic female choice can thus be expressed through bias sperm storage and use in favor of certain males over others(1).
The houbara bustard (Chlamydotis undulata) has a lek mating system(2), which imposes strong sexual selection. Females’ choice is potentially driven by males secondary sexual traits that are expressed during a complex and conspicuous display(3,4). However, females mate with several males in the wild, resulting in frequent multiple paternities within broods(5). Even though it has been shown that female houbara bustards can store sperm, the factors determining sperm storage remain unknown. Yet, sperm storage may play a major role in breeding success and sexual selection in this species.

Research project and objectives.
The Emirates Center for Wildlife Propagation (ECWP) in Morocco is a research and conservation project promoting the restoration of the houbara bustard, as this species inhabiting North Africa is endangered(6). The ECWP aims to sustain wild populations via a captive breeding and reinforcement program(7), producing birds through artificial insemination(8,9) and releasing them in suitable natural areas(10). The master project will be part of a larger project conducted by Pauline Vuarin (post-doctoral fellow at ECWP) and in collaboration with Yves Hingrat, Toni Chalah and Loïc Lesobre (RENECO for wildlife preservation, UAE), Gabriele Sorci (University of Dijon, France), Gwenaëlle Leveque (ECWP), (RENECO) and Michel Saint Jalme (National Museum of Natural History, France). This project aims to investigate post-copulatory mechanisms that may be involved in sexual selection in this bird species.
The student will test if sperm storage duration differs between female houbara bustards, and if so, which female phenotypic traits determine that duration. First, the student will characterize a pre-determined group of females based on their age, body condition and egg lay history (such as mean number of clutch per breeding season and mean number of eggs per clutch) using the ECWP breeding database. The student will collect all eggs that these females will lay following a unique, highly concentrated insemination with a semen mix from males of similar age and spermatic quality. He or she will then determine whether or not these eggs are fertile through a method assessing sperm presence on the oocyte(11). Finally, he or she will test the dependence of sperm storage duration, estimated based on the time after which eggs are no longer fertilized, on female phenotypic traits. Occasionally, the student will also provide help on the evaluation of male semen quality (motility, viability and normality of spermatozoa, ejaculate volume and concentration).

Profile and requirements.
Applicants should be part of a master or engineer program in biology. Specialization in reproductive or evolutionary biology/ecology is desirable. Experience with data handling (excel/access) and statistical analysis (R) would be appreciated. We are looking for a dynamic, rigorous and organized person. Note that the successful candidate will be based at the ECWP in Morocco. Therefore, it is required that applicants are willing to spend several months in a remote place, living within a relatively small community, and able to work in a team and to communicate in French. The internship will last five to six months and will start February 1st 2016, the latest (starting date flexible). Transportation, housing and monthly compensation will be provided.

Application and contacts.
Applicants are requested to send a CV and a cover letter including the contact details of at least one referee to Pauline Vuarin ([email protected]), Yves Hingrat ([email protected]) and Gabriele Sorci ([email protected]), as soon as possible.

1. Birkhead, T. R. & Pizzari, T. Postcopulatory Sexual Selection. Nat. Rev. Genet. 3, 262–273 (2002).
2. Hingrat, Y., Saint Jalme, M., Ysnel, F., Le Nuz, E. & Lacroix, F. Habitat use and mating system of the houbara bustard (Chlamydotis undulata undulata) in a semi-desertic area of North Africa: Implications for conservation. J. Ornithol. 148, 39–52 (2007).
3. Chargé, R., Jalme, M. Saint, Lacroix, F., Cadet, A. & Sorci, G. Male health status, signalled by courtship display, reveals ejaculate quality and hatching success in a lekking species. J. Anim. Ecol. 79, 843–850 (2010).
4. Cornec, C., Hingrat, Y. & Rybak, F. Individual signature in a lekking species: Visual and acoustic courtship parameters may help discriminating conspecifics in the houbara bustard. Ethology 120, 726–737 (2014).
5. Lesobre, L. et al. Absence of male reproductive skew, along with high frequency of polyandry and conspecific brood parasitism in the lekking Houbara bustard Chlamydotis undulata undulata. J. Avian Biol. 41, 117–127 (2010).
6. Goriup, P. D. The world status of the Houbara Bustard Chlamydotis undulata. Bird Conserv. Int. 7, 373–397 (1997).
7. Lacroix, F., Seabury, J., Al Bowardi, M. & Renaud, J. The Emirates Center for Wildlife Propagation: comprehensive strategy to secure self-sustaining wild populations of houbara bustard (Chlamydotis undulata undulata) in Eastern Morocco. Houbara News 5, 60–62 (2003).
8. Chargé, R. et al. Does recognized genetic management in supportive breeding prevent genetic changes in life-history traits? Evol. Appl. 7, 521–532 (2014).
9. Saint Jalme, M., Gaucher, P. & Paillat, P. Artificial insemination in Houbara bustards (Chlamydotis undulata): influence of the number of spermatozoa and insemination frequency on fertility and ability to hatch. J. Reprod. Fertil. 100, 93–103 (1994).
10. Monnet, A.-C., Hardouin, L. a., Robert, A., Hingrat, Y. & Jiguet, F. Evidence of a link between demographic rates and species habitat suitability from post release movements in a reinforced bird population. Oikos 124, 1089–1097 (2015).
11. Croyle, K. E., Durrant, B. S. & Jensen, T. Detection of oocyte perivitelline membrane-bound sperm: a tool for avian collection management. Conserv. Physiol. 3, 1–12 (2015).

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